Mary Costello has written for many years with an occasional story published, but no great encouragement to keep her at her desk. If she is an emerging writer, then she has emerged with great slowness and care. This first collection has the feel of work that refused to be abandoned; of stories that were written for the sake of getting something important right. A few, perhaps the earliest, have an old-fashioned, derivative air, but when she breaks into the world of contemporary Ireland, Costello's work is true, her problems distinctive and the voice all her own.

This is a writer unafraid of the graveside, or the bedside, of filling the space of the story to the brim. Large events happen in small lives – people die, for a start, they fall in and out of love, they have children and affairs. The slow leaking of love out of a relationship is described in particular and terrible banality, as Costello's characters move about their ordinary rooms. There is a kind of immaculate suburban sadness in many of these tales.

Costello's characters are lonely, especially when they are in a relationship. This loneliness is almost precious; it is certainly made sweeter by infidelity. Sexual betrayal is a recurring theme, not just as escape, but as transcendence. In "Sleeping With a Stranger", a school inspector recalls an extramarital episode while sitting with his dying mother. There is no guilt; in fact he experiences something like the opposite of guilt, and the rhapsodic ending recalls the surging epiphanies of Flannery O'Connor.

But though she sometimes likes to sing it out, Costello's best effects are quiet. After his mother stops breathing, the man looks down at her slippers on the floor. "The sight of them, their patient waiting, moved him. He bent down and took them on his lap and put a hand inside each one." This precision, which is so moving, is not only gestural, it is found in the texture of Costello's prose. Leaving his hotel encounter, the man "rose and dressed and went down in the lift, his legs barely able to ferry him". The word "ferry", so natural and particular, unhinges the sentence and lets emotion flood in. It is the accumulation of tiny pleasures such as this that makes The China Factory such a satisfying and accomplished debut.

In "Little Disturbances", a farmer avoids going to the doctor, knowing his test results can not be good. Dying is not a concern; it is life that makes him tremble. He walks the land, steering clear of the "swallow holes" in the bog because he is afraid of "the pull" of water. "There was something in him and he thought the water knew it." When he asks his wife to go to the surgery in his stead, she looks away. "She has a way of being distant that makes him think he is already invisible. One day at the dinner she turned to him and said, 'Can you not chew any quieter?' In winter her eyes are bluer – he used to think the cold got in."

Death is always present in these stories, and it brings a sense of fate that is quite unashamed. Like Alice Munro, Costello is not afraid of a good car accident, a cancer diagnosis, the arrival on the scene of a roaring madman. Like many Irish writers, she does not eschew the child given away in adoption. She writes things that happen all the time but get labelled as "gothic" – perhaps because they happen to most people only once, if at all. Her talent is for placing them in the quotidian. In "The Patio Man" a builder is obliged to drive the woman of the house to hospital as she suffers a miscarriage. To distract themselves along the way, they talk about the house he will build himself someday in the west. "They'll think you're the father," she says, as he parks outside the hospital. As he drives away, alone, he "thinks of things he has not thought of before, about women's lives. It is not the same for men at all."

There is a country cadence in Costello's sentences; her characters yearn westwards towards the Atlantic and the hills and fields of their childhood homes. But she remains true to a dislocation that is more than geographical and is wary of "the landscape solution" so prevalent in Irish prose. Costello insists on the distance between lovers and on the connections between strangers. Her writing has the kind of urgency that the great problems demand – call them themes; they are the kind of problem that make a writer. With a bit of luck, they could keep her at the desk for the rest of her life.